Review Investigates Effects of Intermittent Fasting on BMI, Glycemic Control

An intermittent fasting diet may be beneficial for reducing body mass index (BMI) and improving glycemic control, according to a recent systematic review and meta-analysis published in the Journal of Clinical Medicine.

Intermittent fasting has been growing in popularity as both a method of losing weight and controlling chronic illness such as diabetes. To investigate the effectiveness of the diet, study authors searched various databases for studies that compared intermittent fasting to regular diets or a continuous calorie restriction diet without fasting. They particularly focused on the effects the diet had on BMI and fasting glucose, in addition to other metabolic parameters.

The final analysis included 12 articles involving 545 individuals (261 for intervention vs 284 for control); the studies included patients without chronic metabolic diseases. Results showed that the intermittent fasting diet was associated with a significant reduction in BMI, fasting blood glucose levels, and homeostatic model assessment of insulin resistance levels, when compared with a non-fasting control diet. In addition, decreases in fat mass and leptin levels were noted with the intermittent fasting diet, while lean mass remained mostly unchanged during the intervention.

– Time-restricted fasting: restricting food to specific time periods of the day

– Periodic fasting: fasting only 1-2 days per week

Based on their findings, the authors concluded that the intermittent fasting diet appears to be beneficial, however the association with circadian rhythm warrants further study as previous research has shown that consuming more calories in the morning could significantly improve weight loss and insulin resistance, while skipping breakfast may lead to an increase in stress hormones. “Randomized controlled trials under refined conditions could be helpful to clarify the association with circadian rhythm,” they added.